A roof system generally includes a roof deck which is considered the structural supporting surface of a building extending between the surrounding exterior walls of the building. The roof deck may be constructed from plywood, metal decking or concrete or any other suitable material. Depending upon the construction, the roof deck may extend over the surrounding exterior walls or the roof deck may stop short of the exterior walls thereby forming a parapet wall, i.e., a low retaining wall at the edge of the roof deck. If desired, the roof system may also include an insulation barrier formed from polyisocyanarate or any other suitable material applied over the roof deck.
To make the roof deck and building weather resistant a membrane roof is installed over the roof deck. The membrane roof refers to a water impermeable sheet of polymeric material such as ethylene propylene diene rubber (EPDM), chlorinated polyethylene, polyvinyl chloride, or chlorosulfanated polyethylene. The membrane roof has heretofore been installed on the roof deck using a variety of different methods.
For example, the field or interior of the membrane roof may be held to the roof deck by the use of ballast and/or penetrating or non-penetrating fastener means as known in the art. An example of a penetrating fastener means for retaining the field of a membrane roof installed to a roof deck is by utilizing a plurality of small, circular, metal plates having a hole in the center and a roofing screw or other suitable fastener. In order to anchor the membrane roof, the small, circular, metal plates are spaced apart in rows on the membrane roof and the fastener is driven through the hole in each plate, the membrane roof, any insulation material and then into the roof deck. The metal plates are then covered by overlapping roof membrane. An example of a non-penetrating fastener means would include totally adhering the field of the membrane roof to the roof deck.
However, because the wind uplift forces are not evenly distributed across the roof deck and the perimeter of the roof deck, particularly next to a parapet wall, encounters greater wind uplift forces than are encountered in the field, further consideration must be given to the installation of the membrane roof at the perimeter of the roof deck, e.g., at the parapet wall. Failure to adequately install the membrane roof to the roof deck at the perimeter could cause the membrane roof to separate from the roof deck and/or parapet wall resulting in roof failure and possible damage to the building structure and building interior.
One example of an apparatus for securing a membrane roof to a roof deck at the perimeter of the roof deck is disclosed in U.S. Pat. No. 4,932,171. U.S. Pat. No. 4,932,171 discloses an attachment strip consisting of an EPDM membrane which may or may not be fabric reinforced. The attachment strip is mechanically fastened to the roof deck by fasteners and then an adhesive layer is applied over the attachment strip. Additional adhesive is then applied against the extreme edge of the roof deck and the membrane roof. Next, the membrane roof is pressed against the attachment strip thereby adhesively securing the membrane roof to the attachment strip and to the roof deck.
A membrane roof has also been installed on a roof deck at the perimeter by an attachment strip as disclosed in U.S. Pat. No. 4,885,887. The attachment strip consists of a rubber material such as EPDM and successive layers of an optional primer, an adhesive and a protective layer. The attachment strip is fastened to the roof deck using a bar anchor and then the protective layer is removed exposing the adhesive layer. An optional primer is applied to the bottom surface of the membrane roof and then the membrane roof is pressed against the tape strip adhering the membrane roof to the attachment strip.
Although the many known variations for attaching a membrane roof to a roof deck have been proven to perform satisfactorily under certain conditions, further improvements on attaching a membrane roof to a roof deck are desired.
One object of the present invention is to provide a reinforced tape strip for installing a membrane roof to a roof deck that is simple and economical to manufacture. Another object of the present invention is to provide a method of securing the perimeter of a membrane roof as it abuts against the parapet wall in a manner which reduces labor and material costs but which does not decrease field performance. It is a further object of the present invention to secure the perimeter of a membrane roof using a mechanically fastened reinforced tape strip which is attached to either the parapet wall or to the roof deck at the foot of the parapet wall. The perimeter of the membrane is then adhered to this reinforced tape strip and to the parapet wall. Another object of the present invention is to provide a reinforced tape strip for installing a membrane roof to a roof deck that exhibits superior strength when compared to previous known attachment strips of an equivalent thickness. Yet another object of the present invention is to provide a reinforced tape strip for installing a membrane roof to a roof deck that is flexible and simple to use.